1. Field of the Invention
This invention relates to the structural panel art, and more particularly to a prefabricated structural panel.
2. Description of the Prior Art
It is well known in the structural panel art to provide prefabricated structural panels, and especially panels which have foamed in situ insulation mounted therein and chemically bonded to the inside surface of the panel members. For example, U.S. Pat. Nos. 3,386,218 and 3,535,844 show prefabricated structural panels having foamed in situ insulation. However, a disadvantage of the prior art panels is that they are initially high in cost and difficult to assemble in the field. Some prior art panels have poor thermal insulation values because of through metal. Furthermore, it is costly and time consuming to make repairs on the prior art prefabricated panels. Also, the prior art prefabricated panels have a disadvantage that the foamed in situ urethane insulation has been found to be combustible and flammable, and accordingly, a safety problem is present when such panels are used. Furthermore, the chemical bond holding the bonded insulation in place is not permanent and deteriorates through time and use.